Neutron stars. Magnetic field and rotation. Magneto-rotational braking and the period evolution. Estimate of the magnetic field and of the age from the period and the period derivative. The P-Pdot diagram. Magnetosphere, light cylinder. Goldreich-Julian currents. The Alfven radius, column accretion onto magnetized neutron stars. Internal structure of a neutron star. Neutronization. Neutron star cooling. Neutrino cooling, URCA and modified URCA. Radiative cooling. Cooling curves.